Field
Embodiments of the present disclosure generally relate to a substrate support for use in a substrate processing chamber.
Description of the Related Art
Plasma enhanced chemical vapor deposition (PECVD) is generally employed to deposit thin films on a substrate such as a flat panel or semiconductor wafer. PECVD is generally accomplished by introducing a precursor gas into a vacuum chamber that contains a substrate. The precursor gas is typically directed through a distribution plate situated near the top of the chamber. The precursor gas in the chamber is energized (e.g., excited) into a plasma by applying RF power to the chamber from one or more RF sources coupled to the chamber. The excited gas reacts to form a layer of material on a surface of the substrate that is positioned on a temperature controlled substrate support.
During processing, small local variations in film thickness, often manifesting as spots of thinner film thickness, have been observed which may be detrimental to the device produced. It is believed that variation is glass thickness and flatness, along with a smooth substrate support surface, creates a local capacitance variation in certain locations across the substrate, thereby creating local plasma non-uniformities that leads in deposition variations, e.g., thin spots.
Therefore, there is a need for an improved substrate support.